NSTableView redraw not updating display, selection sticking

Although I know of a solution to this problem, I am interested if someone can explain this solution to me. I also wanted to get this out there because I could not find any mention of this problem online, and it took me several hours over several days to track down. I have an NSTableView behaving strangely regarding redraws and its selection. The problem looks like this:

Table contents fades in, instead of appearing instantly upon it's appearance on screen. When scrolling through the contents, the newly appearing rows also fade in. When you make a selection (single or multiple), and scroll it off screen, then make another selection (that should replace, not add-to first selection), the first selection does not g开发者_运维技巧et cleared properly. If you scroll back to it, it is still there, in addition to your new selection. This is a display-update problem, not selection problem - i.e. your new selection is valid, it is just displayed wrong.

I tracked this through the NSArrayController I was binding to, the underlying Array, sorting, all the connections, and settings, etc., but all that has nothing to do with it.

What solved the problem was: In the View Effects (right-most) Inspector, uncheck "Core Animation Layer" for the Window's main view.

Can anyone explain what is happening here, and perhaps improve upon the solution ?

It looks like Core Animation and NSTableView aren't getting along so well. The "fading" effect is a by-product of the way core animation works. When you have core animation in one view, it is also enabled in all of that view's subviews.

I don't recommend using core animation on the Mac unless absolutely necessary, because some interface elements (NSTextView and NSTableView, for example) aren't compatible with it. iOS has much better support for table views and such using core animation, mainly because it was designed with core animation in mind.

I know that some more simple UI elements are compatible (NSTextField and NSButton, for example).

If you absolutely need core animation in the rest of the window, put all the other views in a subview of the content view, while leaving the table view directly in the content view. You can then enable Core Animation in the other view.

Commenters, feel free to add to the list of what is and isn't compatible.